Semiconductor devices and method of manufacturing the same

A method of manufacturing a semiconductor device, the method comprising:

• etching a portion of a substrate to form active pattern protruding from the substrate;
• conformally forming a first silicon liner having a crystalline structure on surfaces of the active pattern and the substrate;
• oxidizing a surface of the first silicon liner to form a second silicon liner and an insulation layer on the second silicon liner, the second silicon liner having a thickness less than a thickness of the first silicon liner;
• forming an isolation layer on the insulation layer to fill a trench adjacent to the active pattern;
• and,
• forming a transistor, the transistor including
• a gate structure disposed on the second silicon liner, and
• impurity regions, the impurity regions adjacent to respective sides of the gate structure.